The present invention is directed to a shearing machine for textile fabric.
A shearing machine is a machine used in textile industry for cutting the fibers at the surface of fabrics, for cleaning the undesirable fibers from them, for equalizing the height of the pile of fabrics called velvets or imitation furs, or for cutting the top of plush loops on certain fabrics such as terry towel material, in order to give them a uniform surface appearance and thus to imitate velvet.
The cutting of these fibers is ensured by contact between a flat blade and spiral blades. These spiral blades have a helicoidal shape and are mounted on a roll or cutting cylinder. This curing cylinder has a rotational movement in the counterclockwise direction, as viewed from the right-hand side or from left to right in its lower part. As for the flat blade, it is stationary. The rotational movement of the cutting cylinder and of the spiral blades over the flat stationary blade causes an effect of multiblade scissors which cut the fibers.
The cut fibers are removed by strong suction. The friction between spiral blades and the flat blade causes heating of the flat blade, and therefore, there is a tendency to alter the characteristics of the steel and to considerably reduce the cutting duration with the fibers and of proper functioning of the machine. On the other hand, lubricating felt as well as the speed of the rotation of the cylinder tend to hinder the suction and to reduce its effectiveness.
The flat blade, is stationary. It is mounted on a support called the blade holder and immobilized on this blade holder by a blade strap or clamp. As already indicated, this flat stationary blade, blade holder and blade clamp are stationary, but they can be adjusted in a vertical position with respect to the cloth support which allows one to determine the height of the pile of fabric. The rotational movement of the rotary cutting cylinder of spiral blades over the flat stationary blade causes an effect of multiple scissors, as a function of the number of spiral blades which are mounted on the curing cylinder.
The contact between the spiral blades and the flat blade is therefore very important; the good quality of the cutting, the yield, the effectiveness, as well as the longevity of this quality, of this yield, and of this effectiveness depend on it.
Up to now, the contact between the spiral blades and the flat stationary blade has been ensured by either mechanical or electromechanical manual adjustments which exerted pressure on the blade. These adjustments consist of vertical movements of the cutting cylinder using micrometric screws. These movements have the effect of modifying, and as a general rule, of increasing the contact between the spiral blades and the flat stationary blade. These adjustments are approximate, they lack precision, and moreover, they include no indicators showing settings on the control panel of the machine. Consequently, the operator working on the machine has no means of checking the contact pressure existing between the spiral blades and the flat blade. On the other hand, with the flat stationary blade becoming worn because of the friction between the spiral blades and the flat stationary blade, this pressure, which cannot be checked, changes progressively as the flat blade becomes worn. It is therefore necessary to stop the machine from time to time in order to make new adjustments of the contact and pressure between the spiral blades and the flat blade.
The ends of the stationary blade holder are attached on the left part of the frame and the right part of the frame of the machine. This results in deflection in the lengthwise direction. This deflection is amplified by the cutting force between the flat blade and the spiral blades. This deflection contributes towards disturbing the contact between the flat stationary blade and the spiral blades, which is damaging to the high quality of the cutting, to the yield and to the effectiveness of the machine. In order to counteract this deflection, the blade tension device is attached under the blade holder and with the help of one or more tension screws tries to minimize the deflection of the blade holder. Currently these adjustments require stopping of the machine and are themselves also very approximate, imprecise, and without any control or indication on the control board of the machine.
The rotary cutting cylinder can also be adjusted in a horizontal position with respect to the flat stationary blade, so as to adjust, on one hand, the parallelism between the rotary cutting cylinder and the flat stationary blade, and on the other hand, the different cutting positions between the rotary cutting cylinder and the flat blade as a function of the fabric to be treated.
The cloth support can be adjusted in a vertical and horizontal position with respect to the flat stationary blade so as to adjust the vertical and horizontal parallelisms.
This assembly, consisting of the cutting cylinder, the spiral blades, a flat blade, blade strap or clamp, blade holder, and a cloth support therefore has a multitude of different adjustments, all of greatest importance. These adjustments are carried out using micrometric screws, moved either manually or by servomotors.
These and other difficulties experienced with the prior art devices have been obviated by the present invention.
It is therefore, it is an object of the invention to provide a shearing machine wherein the relative position of the cutting edge of the stationary blade relative to the cutting edges of the spiral blades can be adjusted during operation of the machine.
Another object of the invention is to remedy the two problems of heating and suction, by creating and airflow at both sides of the cloth support and through the stationary blade. This has the effect first, of improving the suction, and second, the cooling of the stationary blade.
A further object of the present invention is the provision of a support system for the blade holder which will remedy all these problems of adjustments of contact, adjustments of position, adjustments of pressure between the flat blade and the spiral blades by acting on important points.
A still further object of the invention is to provide pile height adjustment means which acts directly and the holder of the stationary blade for adjusting the position of the cutting edges of the stationary and rotary blades in unison relative to the cloth holder.
It is a further object of the invention to monitor the adjusted position of the stationary and rotary cutting blades relative to the cloth holder and the pressure which is applied to the stationary blade holder, i.e., through electronic sensors and digital display elements.
It is another object of the present invention to facilitate the adjustments and the checking of all these positions by the fitting of optical devices onto the machine, such as microcameras, optical fibers, video screens with graduated or transparent scales.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.